Aviation history abounds of inventions of all sorts to imitate the wing movements of birds. A common objective of these inventions is to enable a person to fly like a bird such as to swiftly take the air or set down at will. Despite all the flying machines known today, it is believed that the mechanism of bird flight has not yet been fully understood and advantageously adapted to flying apparatus. Consequently, many birds and flying insects have been the subject of numerous studies.
Of particular interest is the wing movement of some birds capable of climbing straight up, maintaining a stationary position and even flying backward according to some observations. The wing movement of these birds is that the wings flap down with their broad sides and move up on their edges. The Hummingbird probably represents the best known bird species having such a wing movement. Other bird species having the described wing movement include the Osprey, the Rough-Legged Hawk, the American Kestrel and the Tern.
The wing movement of these birds continues to interest many, mainly because it is believed to represent an ideal concept for developing a compact and versatile flying apparatus capable of taking off and landing without a runway.
Some examples of prior art mechanisms related to the wing movements of ornithopters are described in the following documents:
U.S. Pat. No. 2,021,627 issued on Nov. 19, 1935 to A. T. Gilpin; PA1 U.S. Pat. No. 3,161,376 issued on Dec. 15, 1964 to H. M. Lyle; PA1 U.S. Pat. No. 3,498,574 issued on Mar. 3, 1970 to A. Ernst; PA1 U.S. Pat. No. 4,139,171 issued on Feb. 13, 1979 to J. M. Harris; PA1 U.S. Pat. No. 4,712,749 issued on Dec. 15, 1987 to D. Fox; PA1 U.S. Pat. No. 4,793,573 issued on Dec. 27, 1988 to J. W. Kelfer; PA1 U.S. Pat. No. 5,163,861 issued on Nov. 17, 1992 to G. Van Ruymbeke; PA1 U.S. Pat. No. 5,899,408 issued on May 4, 1999 to K. R. Bowers, Jr.; PA1 GB Patent 885,273 published on Dec. 20, 1961; PA1 DE Patent No. 1,177,941 published on Sep. 10, 1964; PA1 DT Patent 2,706,099 published on Aug. 17, 1978;
Although the ornithopters of the prior art deserve undeniable merits, these apparatus generally have an air plane configuration with relatively wide wing span, and therefore are susceptible of requiring a substantial speed to take the air and to remain airborne.
Therefore it is believed that a need still exists for a compact wing movement which is characterized by a down stroke on the flat side of the wing and an up stroke on the edge of the wing. A need still exists for an effective wing movement which can be built using common technology with common parts and at a reasonable price.